Koito 1881 bulb 12V 21W T20 – Honda 33303-S30-003 / SL4-003 / S2R-901

Koito 1881 bulb 12V 21W T20 – Honda factory fit (33303-S30-003)

Japanese Koito 1881 bulb with parameters 12V 21W and T20 wedge base, used as an original light source in many Honda and Acura models. In Honda applications this Koito bulb was factory fitted under OEM part number 33303-S30-003, and the 1881 marking identifies the same first-fit Koito bulb.

The original Koito bulk box contains 10 bulbs. When you order single pieces from the shop, the bulbs are shipped in a protective replacement pack (not the original 10-pack), safely secured for transport.

Applications

The Koito 1881 12V 21W T20 bulb is used mainly in rear lamps of many Honda/Acura models (brake lights, indicators, reverse lights – depending on lamp design). Example models:

• Acura 2.5 TL, 3.2 TL, 3.5 RL
• Acura RDX 2015–2018, TLX 2015–2020
• Honda Accord 4D 2003–2015
• Honda Accord Tourer 2003–2015
• Honda Accord Coupe 1998–2002
• Honda City 2009–2010
• Honda Civic 3D 2007–2011
• Honda Civic 4D 2007–2021
• Honda Civic 5D 2004–2021
• Honda Civic Coupe 2001–2005
• Honda Civic Hybrid 2004–2011
• Honda CR-V 1997–2018
• Honda CR-Z 2011–2016
• Honda HR-V 1999–2005; 2016–2020
• Honda FR-V 2005–2009
• Honda S2000 2000–2009
• Honda Insight 2000–2013
• Honda Integra 1998–2000
• Honda Jazz 2002–2020
• Honda Legend 4D 1999–2010
• Honda Logo 1999–2000
• Honda Odyssey 1995–2026
• Honda Pilot 2011–2015; 2023–2026
• Honda Prelude 1997–2001
• Honda Shuttle 1998–1999
• Honda Stream 2001–2005

Because lamp design and bulb positions vary between versions, the most reliable way to confirm fitment is to check the OEM part number by VIN or compare with the original bulb and socket.

OEM part numbers

Koito 1881 bulb corresponds to the following genuine Honda bulb numbers:

• 33303-S30-003 – Koito factory-fit bulb in Honda applications
• 33303-SL4-003
• 33303-S2R-901

If one of these numbers is listed for your VIN in the Honda parts catalogue, the Koito 1881 12V 21W T20 bulb is the correct OEM-style replacement.

Typical symptoms and fitting tips

• the light (stop/indicator/reverse) no longer works despite good fuses,
• bulb failure warning on the instrument cluster (where fitted),
• dim, darkened or milky glass, silver deposit inside the bulb,
• intermittent operation – light flickers or goes off when closing the tailgate or driving over bumps.

• switch off lights/ignition before replacing the bulb,
• remove the lamp holder and gently pull the old T20 bulb straight out of the socket,
• check and, if necessary, clean the contacts in the holder,
• avoid touching the glass of the new bulb with bare fingers; if needed, wipe it with a clean cloth,
• after installation, test all functions of the lamp (stop/indicator/reverse etc. depending on use).

FAQ – Koito 1881 12V 21W T20 bulb

Is Koito 1881 the same bulb that was factory-fitted in my Honda?
If your car originally used bulb number 33303-S30-003, then Koito 1881 is the factory Koito bulb – this product is its direct equivalent.

Can I use it instead of 33303-SL4-003 or 33303-S2R-901?
Yes, Koito 1881 12V 21W T20 also replaces these OEM numbers, provided they are specified for your vehicle by VIN.

How is it packed when I order a single bulb?
The original Koito bulk packaging holds 10 bulbs. For smaller quantities, bulbs are shipped in a non-OEM replacement box, properly protected for transport.